Whether you are looking at cameras simply to capture family moments, or as the first step toward a career in photography, the first thing to know as you stare at that bewildering array in the store is the difference between digital and SLR (single lens reflex) cameras. In price, functionality and ease of use, what you don't know could cost you, and leave you with either more or less camera than you wanted.
How SLR Cameras Work
In SLR cameras, an automatic moving mirror system manipulates light entering the camera lens and focuses it onto film or an image sensor at the back of the camera. The photographer determines the focus and how much light enters the camera, in part overriding natural light conditions for better or more interesting shots.
How Digital Cameras Work
Instead of using film to capture the image, digital cameras use an electronic image sensor. The sensor converts the image to electrical signals stored on a memory card as bits of information known as picture elements, or pixels, the base element of all digital photographs.
Essential Differences
Cameras of the "point-and-shoot" digital variety do most of the work through auto-focus, automatic light metering, and a variety of preset modes which compensate for lighting conditions or add special effects. SLR cameras allow the photographer to take control of the shot by manually overriding the camera's choices to change the focus of the image or alter the amount of light reaching the image sensor.
Features
Point-and-shoot cameras often have a single, fixed lens and limited ability to capture quality images in low light or to "freeze" action. SLR cameras have many more functions and can use interchangeable lenses and a wide range of accessories.
Film versus Memory
Digital photos do not have to be developed like film negatives. Because they are simply bits of data, they can be downloaded directly from the camera to a computer and stored, printed, manipulated or shared by the photographer without darkrooms, third parties or expensive specialty equipment.
Film Speed versus Megapixels
Film of different speeds renders different quality photos. In digital cameras, each square pixel represents a tiny fraction of the entire picture, and the quality achieved depends upon the "megapixel" capacity of the camera (the more pixels to the square inch, the higher the quality and the greater the file size of each photo).
Bottom Line
SLRs let you manually adjust settings as well as change lenses, and add on equipment that makes it easier for the photographer to shoot interesting angles. Non-SLR digital cameras are nearly always of the automatic variety in which all the photographer has to do is line up the shot and press the button.
Tags: image sensor, Cameras Work, digital cameras, Digital Cameras